PARIS – Scientists working on a paralysis cure said Tuesday they had demonstrated how a monkey can use only its thoughts, transferred by electrodes, to manipulate a sleeping fellow primate’s arm to do its bidding.
The lab experiment, in which a fully sedated Rhesus monkey’s hand moved a joystick to perform tasks at the other monkey’s command, was designed to simulate full paralysis — the brain completely disconnected from the muscle it seeks to control.
“We demonstrate that a subject can control a paralyzed limb purely with its thoughts,” co-author Maryam Shanechi of Cornell University’s School of Electrical and Computer Engineering said the study in the journal Nature Communications.
The discovery “could have the potential to help paralyzed patients regain control of their own limbs.”
In lab tests, a team of engineers and neuroscientists used electrodes to connect the brain of one monkey to the spinal cord of another via a computer that decoded and relayed the neural signals.
The first monkey, dubbed the “master,” was placed in a special chair before a computer that showed a cursor and a green circle that alternated between two spots. The monkey’s head was restrained. The second animal, or “avatar,” was fully sedated in a separate enclosure — its arm strapped to a 360-degree joystick with which to move the cursor and chase the circular target on the “master’s” screen.
As the master thought of moving the cursor, its brain signals were decoded to determine which of the two targets it had in mind, and the data was relayed in real-time to the spinal cord of the sleeping avatar, whose arm manipulated the joystick accordingly.
Every time the cursor hit its target, the master received a squirt of juice as reward.
Previous research into so-called brain-machine interfaces (BMI) had shown people move computer cursors or even robotic arms using their thoughts.
Shanechi and her team claim they are the first to give an animal control over the actual limb of another animal.
The findings “provide a proof of concept that just by thinking, subjects can move an arm in two dimensions” even with no physiological connection between the brain and the muscle, she said.